A 2.5 mile section of the A21 between Tonbridge and Pembury in Kent will be upgraded from single to dual carriageway, adding a lane in each direction, upgrading junctions and improving the road layout.
Preparatory work on the scheme has been underway since winter 2014 and it is anticipated that the scheme will be fully complete by spring 2017.
Highways Agency Project Manager Graham Link said:
The A21 is a vital route linking the region to the M25 and London. The new section will provide much needed capacity to reduce congestion and will also improve safety with a better road layout and new junctions provided.
The work will start in mid-April and traffic management measures will be necessary. Specific details of these will be available closer to the time
Members of the public should contact the Highways Agency Information Line on 0300 123 5000.
Journalists should contact the Highways Agency press office on 0844 693 1448 and use the menu to speak to the most appropriate press officer.